The significance of changing needles when inoculating blood cultures: a meta-analysis.

Several recent studies have concluded that the changing of needles prior to inoculation of blood culture bottles does not reduce the contamination rate, although there is a consistent trend toward a reduction in number of contaminated cultures when the needle is changed prior to inoculation. We performed a meta-analysis of available studies prospectively comparing blood culture contamination rates with and without a needle change prior to inoculation. The overall weighted contamination rate when the needle was changed prior to inoculation was 2.0%, compared to 3.7% when the needle was not changed. Since an increase of approximately $5,000 in costs per patient is associated with a contaminated blood culture, this reduction in contamination rate could save approximately $85,000 for every 1,000 cultures performed. Our meta-analysis demonstrates reduced blood culture contamination when the needle used for phlebotomy is changed prior to inoculation. This should be considered when setting clinical policy regarding the performance of blood cultures.